1. Filed of the Invention
The disclosed invention relates to an oil pan and transfer case housing assembly.
2. Description of the Related Art
A vehicle which is operated on rough terrain or off-road conditions may encounter situations in which one axle has poor traction due to, for instance, a muddy road, while the other axle has good traction. To solve this problem, a four wheel drive has been provided to such vehicles, such as trucks, sport utility vehicles, and other models suitable for rough terrain or off-road use. Thus, four-wheel drive vehicles are also advantageous on paved roads where traction on each of two axles may be uneven due to snow, ice or rain, as well as during off-road use. These considerations are all well known in the art.
In order to provide a vehicle with four wheel drive, a transfer case must be included somewhere in the drive train in order to transfer some of the drive torque from the engine to the front and rear axles. However, the inclusion of a transfer case in an engine compartment requires more space from what is already a tightly compacted environment. Generally speaking, the more power desired for transfer to the rear axle, the larger the gears must be. Consequently, a housing for the transfer case must be large enough to enclose all of the gears and their associated bearings, resulting in either a smaller clearance between the transfer case and any components adjacent to the transfer case, or in vehicles having an increasingly long longitudinal axis.
Inclusion of a transfer case in an engine compartment also presents an additional problem of increased vibration. While not necessarily in this order, a drive train typically includes a drive shaft, a transmission, and a differential assembly connected to one another in sequence. When components subject to vibration are connected sequentially by linkages, the number of degrees of freedom of movement of individual components is greatly increased. In other words, every bend, twist, compression, decompression, or vibration of one component is magnified by the vibration of every other component in the sequence. When a transfer case is included in the drive train, it additionally magnifies these effects, and could result in an unacceptably high level of vibration of the drive train and other components mounted in the engine compartment. Increased vibration is undesirable because it reduces driver and passenger comfort, increases road noise, and loosens parts and linkages.
Therefore, there is a need in the art for a transfer case housing and engine oil pan assembly that introduces an acceptable level of vibration to the drive train and provides increased available space for larger gears in the transfer case.